Speaking as a Californian, dams on the Sacramento and San Joaquin rivers have reduced our salmon migrations to only 5% of their pre-dam-building norms. My ques

Speaking as a Californian, dams on the Sacramento and San Joaquin rivers have reduced our salmon migrations to only 5% of their pre-dam-building norms. My question for Norwegians: Have you seen similar environmental impacts on their native fisheries and ecosystems due to your large-scale hydroelectric constructions?